Deficient adenylate cyclase regulatory protein in renal membranes from a patient with pseudohypoparathyroidism.

Abstract

Recent studies have established that some patients with pseudohypoparathyroidism have a deficiency of the adenylate cyclase regulatory protein (the G unit) in plasma membranes from erythrocytes, platelets, and fibroblasts. We have directly measured the activity of the G unit in renal membranes from a patient with pseudohypoparathyroidism who, in addition to parathyroid hormone resistance, has resistance to thyrotropin and gonadotropins. Erythrocyte membrane G unit activity was 57% that of control erythrocyte membranes. Lubrol PX extracts of renal membranes had only 30% of the G unit activity of control renal membrane extracts, whether assayed with sodium fluoride or guanosine-5'-O-(3-thiotriphosphate) (GTP-gamma-S). In cholate extracts, the G unit activity was 37 and 48% of control with fluoride or GTP-gamma-S, respectively. Cholera toxin-dependent incorporation of [32P]ADP-ribose into the 42,000-Mr subunit of the G unit was decreased in renal membranes from the patient compared with control renal membranes. The data demonstrate that the membrane G unit deficiency in pseudohypoparathyroidism extends to the cells of a clinically relevant parathyroid hormone target tissue.

• Authors: R W Downs Jr, M A Levine, M K Drezner, W M Burch Jr, A M Spiegel
• Journal: The Journal of clinical investigation (J Clin Invest) Vol. 71 Issue 2 Pg. 231-5 (Feb 1983) ISSN: 0021-9738 [Print] United States
• PMID: 6822662 (Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Adenylyl Cyclases

Topics

• Adenylyl Cyclases (deficiency)
• Adolescent
• Erythrocyte Membrane (enzymology)
• Female
• Humans
• Kidney (enzymology)
• Molecular Weight
• Pseudohypoparathyroidism (enzymology)